#include "junix.h"
using namespace std;

int main(int argc, char **argv)
{
	string s="hello,world!";
	cout<<s<<endl;
	cout<<s.substr(1)<<endl;
	cout<<s.substr(1,3)<<endl;
	cout<<s.substr(1,33)<<endl;
	cout<<s.substr(5,-2)<<endl;
	cout<<s.substr(5,0)<<endl;
	cout<<s.substr(5)<<endl;
	cout<<s.substr(s.find(",")+1)<<endl;
	cout<<s.substr(s.find(","))<<endl;
}
